Interference Fringes and Diffraction Gratings

1. Chapter 24

2. Suppose the viewing screen in the figure is moved closer to the double slit. What happens to the interference fringes? • They get brighter but otherwise do not change. • They get brighter and closer together. • They get brighter and farther apart. • They get out of focus. • They fade out and disappear.

3. Suppose the viewing screen in the figure is moved closer to the double slit. What happens to the interference fringes? • They get brighter but otherwise do not change. • They get brighter and closer together. • They get brighter and farther apart. • They get out of focus. • They fade out and disappear.

4. Light of wavelength l1 illuminates a double slit, and interference fringes are observed on a screen behind the slits. When the wavelength is changed to l2, the fringes get closer together. How large is l2 relative to l1? • l2 is larger than l1. • l2 is smaller than l1. • Cannot be determined from this information.

5. Light of wavelength l1 illuminates a double slit, and interference fringes are observed on a screen behind the slits. When the wavelength is changed to l2, the fringes get closer together. How large is l2 relative to l1? • l2 is larger than l1. • l2 is smaller than l1. • Cannot be determined from this information.

6. White light passes through a diffraction grating and forms rainbow patterns on a screen behind the grating. For each rainbow, • the red side is on the right, the violet side on the left. • the red side is on the left, the violet side on the right. • the red side is closest to the center of the screen, the violet side is farthest from the center. • the red side is farthest from the center of the screen, the violet side is closest to the center.

7. White light passes through a diffraction grating and forms rainbow patterns on a screen behind the grating. For each rainbow, • the red side is on the right, the violet side on the left. • the red side is on the left, the violet side on the right. • the red side is closest to the center of the screen, the violet side is farthest from the center. • the red side is farthest from the center of the screen, the violet side is closest to the center.

8. A Michelson interferometer using light of wavelength l has been adjusted to produce a bright spot at the center of the interference pattern. Mirror M1 is then moved distance l toward the beam splitter while M2 is moved distance l away from the beam splitter. How many bright-dark-bright fringe shifts are seen? • 0 • 1 • 2 • 3 • 4

9. A Michelson interferometer using light of wavelength l has been adjusted to produce a bright spot at the center of the interference pattern. Mirror M1 is then moved distance l toward the beam splitter while M2 is moved distance l away from the beam splitter. How many bright-dark-bright fringe shifts are seen? • 0 • 1 • 2 • 3 • 4

10. What was the first experiment to show that light is a wave? • Young’s double slit experiment • Galileo’s observation of Jupiter’s moons • The Michelson-Morley interferometer • The Pound-Rebka experiment • Millikan’s oil drop experiment

11. What was the first experiment to show that light is a wave? • Young’s double slit experiment • Galileo’s observation of Jupiter’s moons • The Michelson-Morley interferometer • The Pound-Rebka experiment • Millikan’s oil drop experiment

12. What is a diffraction grating? • A device used to grate cheese and other materials • A musical instrument used to direct sound • A plaque with a tiny circular aperture • An opaque objects with many closely spaced slits • Diffraction gratings are not covered in Chapter 22.

13. What is a diffraction grating? • A device used to grate cheese and other materials • A musical instrument used to direct sound • A plaque with a tiny circular aperture • An opaque objects with many closely spaced slits • Diffraction gratings are not covered in Chapter 22.

14. When laser light shines on a screen after passing through two closely spaced slits, you see • a diffraction pattern. • interference fringes. • two dim, closely spaced points of light. • constructive interference.

15. When laser light shines on a screen after passing through two closely spaced slits, you see • a diffraction pattern. • interference fringes. • two dim, closely spaced points of light. • constructive interference.

16. The spreading of waves behind an aperture is • more for long wavelengths, less for short wavelengths. • less for long wavelengths, more for short wavelengths. • the same for long and short wavelengths. • not discussed in this chapter.

17. The spreading of waves behind an aperture is • more for long wavelengths, less for short wavelengths. • less for long wavelengths, more for short wavelengths. • the same for long and short wavelengths. • not discussed in this chapter.

18. Apertures for which diffraction is studied are • a single slit. • a circle. • a square. • both A and B. • both A and C.

19. Apertures for which diffraction is studied are • a single slit. • a circle. • a square. • both A and B. • both A and C.